JPH04304485A - Developing device - Google Patents

Abstract

PURPOSE:To eliminate a dead space and to prevent the remaining of dead toner by providing a cylindrical waste toner recovery container concentric with the rotational center of an agitator inside a toner replenishing hopper. CONSTITUTION:A hollow cylindrical waste toner recovery container 13 is supported on a hopper housing toner, and the hopper is almost cylindrically formed centering the center axis of the waste toner recovery container 13. At this time, the inside of the hopper is divided into two layer spaces by the cylindrical wall of the waste toner recovery container 13, and an inside space 16 is formed as a waste toner recovery part and an outside space 15 is formed as an unused toner part housing unused toner, as a waste toner recovery part. Thus, the unused toner and waste toner can be contained inside a compact hopper, and the rotational center of the agitator 17 can be concentrically formed, as well so that the dead space is hardly formed inside the hopper, but the toner can be stirred. Further, the occurrence of the dead toner can be prevented and maintenance can be facilitated, as well.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an image forming apparatus such as a copying machine, a printer, or a facsimile machine.

0002

2. Description of the Related Art Many image forming apparatuses such as electrophotographic copying machines are constructed to develop a latent image on a latent image carrier with toner to form a toner image, and then transfer the toner image to transfer paper. The residual toner on the latent image carrier is removed by a cleaning device and collected in a waste toner collection container.

[0003] Conventionally, it has been put into practical use to form a developing device, a cleaning device, etc. into a replaceable cartridge, but since the lifespan of each component differs, the replacement period differs, and the developing device and cleaning device are separated. This is preferable from the viewpoint of longevity. In this case, if the waste toner collecting container collected by the cleaning device is used for too long, the amount of collected toner will increase and a large space will be required. Since the time interval during which the developing device is attached and detached for toner replenishment is short, it has been proposed, for example, in Japanese Patent Publication No. 10424/1983, to house the waste toner collection container in the cartridge of the developing device. In conventional devices, the unused toner storage section and the waste toner collection section are arranged one above the other, and the problem is that the waste toner collection section becomes a waste of space and requires a larger space than necessary.

0004

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a developing device including a waste toner collection section that is compact, easy to handle, and easy to maintain. .

[0005]

[Means for Solving the Problems] The present invention solves the above problems by providing a developing roller that conveys and develops toner on a latent image on a latent image carrier, a hopper that stores toner for replenishment, and a container inside the hopper. In a developing device having an agitator for agitating toner and replenishing the toner to the developing roller, a hollow cylindrical waste toner collection container is provided in the hopper and is concentric with the center of rotation of the agitator, and a waste toner collection section and an unused toner collection container are provided in the hopper. The problem has been solved by a developing device characterized in that a storage section is formed in two layers separated by the waste toner collection container. In this case, the agitator may have a structure including a support member that slides and rotates on the outer peripheral surface of the waste toner collection container, and a wing portion that is fixed to the support member.

[0006]

[Operation] According to the present invention, a hollow cylindrical container concentric with the rotation center of the agitator is provided in the toner replenishment hopper having an agitator as a waste toner collection container, and a waste toner collection section in the center and an unused toner section on the outer periphery are separated. It is separated and formed into two layers. Therefore, by forming the hopper into a substantially cylindrical shape, the unused toner is sufficiently agitated by the agitator.
Since dead toner does not remain in the container and the hopper container is also shaped into a substantially cylindrical shape, it has become possible to obtain a compact developing device. By providing the waste toner collection section at the center of rotation of the agitator, it has become possible to use space effectively.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained based on the embodiments shown in the drawings.

In FIG. 1, a latent image carrier 1 of an image forming apparatus, such as a photoreceptor belt, is charged by a charging roller 2, exposed to image light 3 from an image exposure device to form an electrostatic latent image, and then developed. The toner is developed by the developing roller 5 of the device 4 to form a toner image.

The toner image on the photoreceptor belt 1 is transferred to a transfer paper 6 fed from a paper feeding device (not shown) under the action of a transfer roller 7, and the transferred paper is fixed by a fixing device (not shown) and then discharged. be done. After the transfer, residual toner is removed from the photoreceptor belt 1 by a cleaning device 8, and the next steps from charging by the charging roller 2 are repeated.

As shown in FIGS. 1 to 3, the developing device 4 has a case 10 to which a hopper 9 containing toner can be fixed or integrally formed, and a developing roller 5 and a developing roller 5 are disposed in the case 10.
A replenishment roller 11 that replenishes toner to the developing roller 5 is rotatably supported, and a blade 12 that forms the toner layer of the developing roller 5 into a thin layer of uniform thickness is fixed.

A hollow cylindrical waste toner collection container 13 is supported on the hopper 9;
Advantageously, it is formed into a substantially cylindrical shape centered on the central axis of.

Inside the hopper 9 is a waste toner collection container 13.
The cylindrical wall separates the space into two layers: an external space 15 and an internal space 16. The internal space 16 is formed as a waste toner collection section that stores waste toner, and the external space 15 is formed as an unused toner section that stores unused toner. is formed as.

An agitator 17 is provided to agitate the toner in the external space 15 and replenish the toner toward the replenishment roller 10, that is, toward the developing roller 5.

As shown in FIG. 4, the waste toner collection container 13 has an engaging protrusion 18 at one end, and this engaging protrusion 18 engages with the engaging groove of the hopper 9 and is held so as not to rotate. . A collection inlet 19 is opened at the other end of the waste toner collection container 13, and a shaft 22 of a gear 21 is rotatably supported in a bearing hole 20 provided at the end near the collection entrance 19. A spiral conveyance screw 23 is disposed in the hollow part of the waste toner collection container 13, and one end of the conveyance screw 23 is connected to the shaft 2.
The conveyance screw 23 rotates as the gear 21 rotates, and conveys the waste toner from the collection entrance 19 to the opposite side. A cover 24 that covers the collection inlet 19 is attached to the outer peripheral surface of the waste toner collection container 13 so as to be movable in the axial direction, and is normally formed to cover the collection inlet 19 with a spring 25 .

The agitator 17 is formed to be rotatable about the center line of the waste toner collection container 13, and includes, for example, an annular front support member 26 that is slidably and rotatably attached to the outer peripheral surface of the waste toner collection container 13. and an annular rear support member 27
One or more, in the example shown in the figure, two connecting beams 28 are provided to connect the front support member 26 and the rear support member, and each connecting beam 28 is provided with stirring blades 29, for example. Made of Mylar (trade name). If an appropriate number of blades 29 are configured to be rotatable concentrically with the waste toner collection container 13,
It is not limited to the structure shown in the figure. two support members 2
6 and 27 as one member, and the wing 29 is directly attached to the supporting member.
can also be formed.

A gear 30 is fixed to the support member (rear support member 27 in the figure), and the blade 29 of the agitator 17 is rotated by the gear 30.

When the agitator 17 is installed in the hopper 9, in the illustrated example, both ends of the agitator 17 are rotatably supported near both ends of the waste toner collection container 13.

When the developing device 4 is installed inside the image forming apparatus, as shown in FIGS. 3 and 5, it is connected to the recovered toner outlet of the cleaning device 8, has a conveyance screw 31 inside, and is attached along the side plate 33. The outlet end of the extending waste toner conveying pipe 32 is connected to the inlet 19 in a state where the cover 24 is pushed open.

The toner collected in the cleaning device 8 is transported into the waste toner transport pipe 32 by the transport screw 40 and dropped, and is transported inside the waste toner transport pipe 32 toward the developing device 4 by the transport screw 31, where it is disposed of as waste. The toner is fed into the toner collection container 13 from the inlet 19.

When the developing device 4 is attached, the gear 3 of the drive section of the main body
7 meshes with a gear 38 provided on the developing roller 5, and the developing roller 5 is driven. At this time, the rotation of the developing roller 5 causes the supply roller 11 to pass through the gear 34, the idle gear 35, and the gear 3.
Power is transmitted through the mesh of 6. The gear 36 meshes with the idle gear 35 and at the same time meshes with the gear 30 of the agitator 17 to rotate the agitator 17. Also supply roller 1
A gear 39 that is rotatably supported by the waste toner collection container 13 and meshes with the gear 21 is fixed to the shaft of the conveyor screw 23 .
is also rotated. While the developing roller 5 is rotating, the waste toner is transported to the front inside the waste toner collection container 13.

When the toner in the hopper 15 runs out and the developing device 4 is replaced, the waste toner collection container 13 can also be removed.

[0022]

According to the present invention, the hopper is separated into two substantially concentric cylindrical layers by the waste toner collection container, and it has become possible to accommodate waste toner and unused toner in the compact hopper. Furthermore, since the rotation centers of the agitators are concentric, the toner can be agitated without forming almost any dead space in the hopper, and the generation of dead toner can be prevented.

According to the present invention, the waste toner collection container is located inside the hopper and its depth is approximately the same as the length of the hopper, so the entire hopper can be made compact and the container capacity can be increased. In addition, the overall shape of the developing device can be made into a nearly cylindrical shape that is not unnatural and leads to improved handling, and maintenance by the user has become easier.

[0024] According to the present invention, the agitator can be slid and rotated on the outer peripheral surface of the waste toner collection container, making it possible to almost completely eliminate dead space.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of an image forming apparatus using a developing device according to the present invention.

FIG. 2 is a partially cutaway perspective view of the developing device.

FIG. 3 is a sectional view of the developing device.

FIG. 4 is an exploded perspective view of the hopper internal member.

FIG. 5 is a plan view of a portion of the image forming apparatus when the developing device is attached.

[Explanation of symbols]

1 Latent image carrier 4 Developing device 5 Developing roller 9 Hopper 13 Waste toner collection container 15 Unused toner storage section 16 Waste toner collection department 17 Agitator

Claims (2)

[Claims] 1. A developing roller that conveys and develops toner on a latent image on a latent image carrier, a hopper that stores toner for replenishment, and an agitator that agitates the toner in the hopper and replenishes the toner to the developing roller. In the developing device, a hollow cylindrical waste toner collection container concentric with the rotation center of the agitator is provided in the hopper, and a waste toner collection section and an unused toner storage section are arranged in two layers by the waste toner collection container. A developing device characterized by being formed separately. 2. The developing device according to claim 1, wherein the agitator includes a support member that slides and rotates on the outer peripheral surface of the toner collection container, and a wing portion that is fixed to the support member.